                <script src="<?php echo base_url('public_source/javascript/jquery-1.9.1.js');?>" type="text/javascript"></script>
<script src="<?php echo base_url('public_source/javascript/jquery-ui.js');?>" type="text/javascript"></script>
<script>
        $(document).ready(function(){
                $("#sg select").change(function(){
		$.ajax({
			type: "POST",
			url: "<?php echo site_url("home_admin/ajax_getdong2") ?>",
			data: {mahang : $(this).val()},
			async: true,
			beforeSend: function(){
				$("#result").html("");
			},
			success: function(kq){
				$("#result").html(kq);
			}
		});
		return false;
                });
        });
        
        </script>
    <div id="result">
<?php

echo "<select id='dong' name='dong'>";
    foreach ($dong as $item)
    {
        echo "<option value='".$item["fldMaDong"]."'>";
        echo $item["fldTenDong"];
        echo "</option>";
    }
echo "</select>"
?>
        </div>